Computational load distribution in a climate control system having plural sensing microsystems

ABSTRACT

Systems, methods, and related computer program products for controlling one or more HVAC systems using a distributed arrangement of wirelessly connected sensing microsystems are described. A plurality of wirelessly communicating sensing microsystems is provided, each sensing microsystem including a temperature sensor and a processor, at least one of the sensing microsystems being coupled to an HVAC unit for control thereof. The plurality of sensing microsystems is configured to jointly carry out at least one shared computational task associated with control of the HVAC unit. Each sensing microsystem includes a power management circuit configured to determine an amount of electrical power available for dedication to the at least one shared computational task. The at least one shared computational task is apportioned among respective ones of the plurality of sensing microsystems according to the amount of electrical power determined to be available for dedication thereto at each respective sensing microsystem.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Prov. Ser. No. 61/429,093filed Dec. 31, 2010 and U.S. Prov. Ser. No. 61/415,771 filed Nov. 19,2010, each of which is incorporated by reference herein. The subjectmatter of this provisional patent specification relates to the subjectmatter of the following commonly assigned applications: U.S. Ser. No.12/881,430 filed Sep. 14, 2010; U.S. Ser. No. 12/881,463 filed Sep. 14,2010; U.S. Ser. No. 12/987,257 filed Jan. 10, 2011; U.S. Ser. No.13/034,666 filed Feb. 24, 2011; U.S. Ser. No. 13/034,674 filed Feb. 24,2011; and U.S. Ser. No. 13/034,678 filed Feb. 24, 2011. Each of theabove-referenced patent applications is incorporated by referenceherein. The above-referenced patent applications are collectivelyreferenced hereinbelow as “the commonly assigned incorporatedapplications.”

FIELD

This patent specification relates to system monitoring and control, suchas to the monitoring and control of heating, cooling, and airconditioning (HVAC) systems. More particularly, this patentspecification relates to systems, methods, and related computer programproducts for controlling one or more systems, such as HVAC systems,using a distributed arrangement of wirelessly connected sensing andcontrol units.

BACKGROUND AND SUMMARY

Substantial effort and attention continues toward the development ofnewer and more sustainable energy supplies, the conservation of energyby increased energy efficiency remains crucial to the world's energyfuture. According to an October 2010 report from the U.S. Department ofEnergy, heating and cooling account for 56% of the energy use in atypical U.S. home, making it the largest energy expense for most homes.Along with improvements in the physical plant associated with homeheating and cooling (e.g., improved insulation, higher efficiencyfurnaces), substantial increases in energy efficiency can be achieved bybetter control and regulation of home heating and cooling equipment. Byactivating heating, ventilation, and air conditioning (HVAC) equipmentfor judiciously selected time intervals and carefully chosen operatinglevels, substantial energy can be saved while at the same time keepingthe living space suitably comfortable for its occupants.

For the purposes of controlling one or more HVAC systems for climatecontrol in an enclosure, systems for that incorporate a distributedarray of wirelessly communicating sensing units are known in art anddiscussed, for example, in U.S. Pat. No. 5,395,042, which isincorporated by reference herein. Different methods for powering thewirelessly communicating sensing units are also known in the art,including using standard building AC outlet power as discussed inUS20080015740A1, standard battery-only power as discussed inUS20070114295A1, and solar-charged battery power as discussed U.S. Pat.No. 5,395,042, supra. For wirelessly communicating thermostatic sensingunits having control wires running directly to a conventional HVACsystem, so-called “power stealing” or “parasitic powering” methods suchas those discussed in U.S. Pat. No. 7,510,126 can be used, wherein arelatively small amount of power is extracted from a call relay coilvoltage provided by the HVAC system. Each of the above-cited patents andpatent publications is incorporated by reference herein.

For the purposes of controlling one or more HVAC systems for climatecontrol in an enclosure, various computational methods have beenproposed for optimizing the control of one or more HVAC systems in amanner that accommodates a balance of human comfort and energyefficiency, the optimizing being based at least in part on current andhistorical environmental readings and inputs acquired at a distributednetwork of sensing nodes. Examples of such proposals are discussed inU.S. Pat. No. 7,847,681 B2 and US20100262298A1, each of which isincorporated by reference herein. Generally speaking, such computationalmethods can involve multidimensional feedback control systemcharacterization or “learning” of a climate control environment havingone or more HVAC systems and/or simultaneous optimization of pluralmultidimensional feedback control system performance metrics (such as a“total suffering” metric described in US20100262298A1, supra) based onlearned or known multidimensional feedback control system parameters andconstraints characteristic of the climate control environment. Suchcomputational tasks, which are termed “characterization and/oroptimization algorithms” hereinbelow for clarity of description and notby way of limitation, can be of relatively high computational complexityand therefore can represent a relatively high computational load.

Provided according to an embodiment is a climate control systemcomprising a plurality of wirelessly communicating sensing microsystems,each sensing microsystem including a temperature sensor and a processor,at least one of the sensing microsystems being coupled to an HVAC unitfor control thereof. The plurality of sensing microsystems is configuredto jointly carry out at least one shared computational task associatedwith the control of the HVAC unit. Each sensing microsystem includes apower management circuit configured to determine an amount of electricalpower available for dedication to the at least one shared computationaltask. The at least one shared computational task is apportioned amongrespective ones of the plurality of sensing microsystems according tothe amount of electrical power determined to be available for dedicationthereto at each respective sensing microsystem.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1C illustrate external views of a sensing microsystem accordingto an embodiment;

FIG. 2A illustrates a building enclosure including plural sensingmicrosystems and an HVAC system according to an embodiment;

FIG. 2B illustrates a conceptual diagram of an HVAC system as wired to asensing microsystem according to an embodiment;

FIGS. 3A-3C illustrate examples of building enclosures including pluralsensing microsystems and one or more HVAC systems according to one ormore embodiments;

FIG. 4 illustrates a sensing microsystem and a conceptual functionalblock diagram thereof according to an embodiment;

FIG. 5 illustrates shared computational load distribution in a climatecontrol system having plural sensing microsystems according to anembodiment; and

FIG. 6 illustrates shared computational load distribution in a climatecontrol system having plural sensing microsystems according to anembodiment.

DETAILED DESCRIPTION

One or more of the embodiments described herein is particularlyadvantageous for use with climate control systems having pluralwirelessly communicating sensing microsystems, such as those describedin one or more of the commonly assigned incorporated applications,supra. More particularly, one or more of the embodiments describedherein is particularly advantageous in the practical implementation ofan easy-to-install, easy-to-administer, flexible, and scalable networkof smart, visually appealing, “lightweight” sensing and control nodes,referenced herein as sensing microsystems, that cooperate to govern theoperation of one or more HVAC systems in a manner that promotes anoptimal balance of human comfort and energy efficiency for an enclosure,such as a residential or business building enclosure. By “lightweight,”it is meant that that the sensing microsystems are relatively compactand low-powered devices, comparable in size to handheld devices such assmartphones, and consuming relatively low amounts of electrical power,such as 10 watts or less. Lightweight computing devices, as that term isused herein, can be contrasted with computing devices having relativelyheavy power usage, such as desktop computers whose average energy usageis often in the hundred as watts, and such as laptop or notebookcomputers whose average energy usage is generally well over 10 watts,and rarely under 20 watts. It is to be appreciated that while the abovenumerical examples provide a fair characterization of a “lightweight”computing device by current technological standards, one skilled in theart would be readily aware that a lesser dividing line, such as 1 wattor less of average energy usage, may provide a fair characterization ofwhat is meant by a lightweight computing device as more energy-efficientmicroprocessor technologies are hereinafter developed.

It is to be appreciated that while one or more embodiments is detailedherein for the context of a residential home, such as a single-familyhouse, the scope of the present teachings is not so limited, the presentteachings being likewise applicable, without limitation, to duplexes,townhomes, multi-unit apartment buildings, hotels, retail stores, officebuildings, industrial buildings, and more generally any living space orwork space having one or more HVAC systems. It is to be furtherappreciated that while the terms user, customer, installer, homeowner,occupant, guest, tenant, landlord, repair person, and the like may beused to refer to the person or persons who are interacting with thesensing microsystem or other device or user interface in the context ofsome particularly advantageous situations described herein, thesereferences are by no means to be considered as limiting the scope of thepresent teachings with respect to the person or persons who areperforming such actions.

FIGS. 1A-1C illustrate external views of a sensing microsystem 100 forwhich shared computational load distribution in a climate control systemhaving plural such sensing microsystems according to one or moreembodiments is particularly suitable. For some embodiments, the sensingmicrosystem 100 corresponds to one or more of the intelligent,wirelessly communicating thermostatic units (termed in Ser. No.61/429,093, supra, as a versatile sensing and control unit or VSCU)described in one or more of the commonly assigned incorporatedapplications, supra. As facilitated by its lightweight character,sensing microsystem 100 preferably has a sleek, elegant appearance thatdoes not detract from home decoration, and indeed can serve as avisually pleasing centerpiece for the immediate location in which it isinstalled. The sensing microsystem 100 comprises a main body 108 that ispreferably circular with a diameter of about 8 cm, and that has avisually pleasing outer finish, such as a satin nickel or chrome finish.Separated from the main body 108 by a small peripheral gap 110 is acap-like structure comprising a rotatable outer ring 106, a sensor ring104, and a circular display monitor 102. The outer ring 106 preferablyhas an outer finish identical to that of the main body 108, while thesensor ring 104 and circular display monitor 102 have a common circularglass (or plastic) outer covering that is gently arced in an outwarddirection and that provides a sleek yet solid and durable-lookingoverall appearance. The sensor ring 104 contains any of a wide varietyof sensors including, without limitation, infrared sensors,visible-light sensors, and acoustic sensors. Preferably, the glass (orplastic) that covers the sensor ring 104 is smoked or mirrored such thatthe sensors themselves are not visible to the user. An air ventingfunctionality is preferably provided, such as by virtue of theperipheral gap 110, which allows the ambient air to be sensed by aninternal temperature sensor and any other internal sensors.

As discussed elsewhere in the commonly assigned incorporatedapplications, supra, for one embodiment the sensing microsystem 100 iscontrolled by only two types of user input, the first being a rotationof the outer ring 106 (FIG. 1B), and the second being an inward push onthe outer ring 106 (FIG. 1C) until an audible and/or tactile “click”occurs. By virtue of user rotation of the outer ring 106 and the inwardpushing of the outer ring 106 responsive to intuitive and easy-to-readprompts on the circular display monitor 102, the sensing microsystem 100is advantageously capable of receiving all necessary information fromthe user for basic setup and operation.

FIG. 2A illustrates a plurality of wirelessly communicating sensingmicrosystems according to an embodiment, including a primary sensingmicrosystem 100 and an auxiliary sensing microsystem 100′, as installedin a house 201 having an HVAC system 299 and a set of control wires 298extending therefrom. The primary sensing microsystem 100 is connected tothe HVAC system 299 by the control wires 298 for control thereof, whilethe auxiliary sensing microsystem 100′ is disposed in a cradle ordocking station 205 and placed, for example, on a nightstand 288 locatedin a bedroom of the house 201. As used herein, the term “primary sensingmicrosystem” refers to one that is electrically connected to actuate anHVAC system in whole or in part, which would necessarily include thefirst sensing microsystem purchased for any home, while the term“auxiliary sensing microsystem” or “remote sensing microsystem” refersto one or more additional sensing microsystems not electricallyconnected to actuate an HVAC system in whole or in part.

The primary sensing microsystem 100 and auxiliary sensing microsystem100′ are each configured to automatically recognize the presence of theother and to communicate with each other using a wireless communicationprotocol such as Wi-Fi, ZigBee, or Z-Wave, represented generically inFIG. 2A by the electromagnetic radiation signals R. The wirelesscommunications among the multiple sensing microsystems can be achievedin a networked fashion using a home wireless router (not shown), on anad hoc or peer-to-peer basis, various combinations thereof, or any othermethod that can be used to achieve wireless communication thereamong. Inone example, the primary sensing microsystem 100 of FIG. 2A receives itselectrical power by virtue of a power-stealing scheme, wherein arelatively small amount of power is extracted from a call relay coilvoltage provided by the HVAC system. In one example, the auxiliarysensing microsystem 100′ of FIG. 2A is powered from a building AC outlet286, more particularly, by AC adapter circuitry (not shown) located inthe docking station 205 and/or by an external “power brick” AC adapter(not shown) connected between docking station 205 and the wall outlet286. In another examples, the primary sensing microsystem 100 of FIG. 2Areceives its power from a common (C) HVAC signal wire provided by theHVAC system 299 as one of the control wires 298, while the auxiliarysensing microsystem 100′ could be powered by standard alkaline orlithium batteries. As used herein, the term “continuous line power”refers to power that is provided by a generally continuous, reliablesource such that, for normal everyday operational purposes, it can beassumed that such power will be ongoing and not drained or otherwisetime-limited. For purposes of the instant disclosure, examples ofcontinuous line power includes power provided from standard 110-volt ACwall outlets, and power provided by the common (C) wire of an HVACsystem. Notably, not all HVAC systems provide a common (C) wire, therebygiving rise to a need for the above-described power-stealing schemes forsome primary sensing microsystem installations. For purposes of thepresent disclosure, power sources such as stand-alone lithium oralkaline batteries, power-stealing arrangements (with or withoutassociated rechargeable batteries), and rooftop- or window-mounted solarpower sources (with or without associated rechargeable batteries) wouldrepresent examples of power sources that are not continuous line powersources.

FIG. 2B illustrates an exemplary diagram of the HVAC system 299 of FIG.2A. HVAC system 299 provides heating, cooling, ventilation, and/or airhandling for an enclosure, such as the single-family home 201 depictedin FIG. 2A. The HVAC system 299 depicts a forced air type heatingsystem, although according to other embodiments, other types of systemscould be used. In heating, heating coils or elements 242 within airhandler 240 provide a source of heat using electricity or gas via line236. Cool air is drawn from the enclosure via return air duct 246through filter 270 using fan 238 and is heated by the heating coils orelements 242. The heated air flows back into the enclosure at one ormore locations through a supply air duct system 252 and supply airgrills such as grill 250. In cooling, an outside compressor 230 passes agas such as Freon through a set of heat exchanger coils to cool the gas.The gas then goes via line 232 to the cooling coils 234 in the airhandlers 240 where it expands, cools and cools the air being circulatedthrough the enclosure via fan 238. According to some embodiments ahumidifier 262 is also provided which moistens the air using waterprovided by a water line 264. Although not shown in FIG. 2B, accordingto some embodiments the HVAC system for the enclosure has other knowncomponents such as dedicated outside vents to pass air to and from theoutside, one or more dampers to control airflow within the duct systems,an emergency heating unit, and a dehumidifier. The HVAC system isselectively actuated via control electronics 212 that communicate withthe primary sensing microsystem 100 over control wires 298.

FIGS. 3A-3C illustrate examples of building enclosures including pluralsensing microsystems and one or more HVAC systems according to one ormore embodiments, and are set forth to illustrate but a few examples ofthe wide variety of different combinations of primary sensingmicrosystems, auxiliary sensing microsystems, and HVAC systems that canused in conjunction with one or more of the preferred embodiments. Thus,for example, in FIG. 3A the house 201 contains a second HVAC system 399that is wired to a second primary sensing microsystem 100″ over a set ofcontrol wires 398, the second primary sensing microsystem 100″ beingpowered by a power-stealing scheme with HVAC system 399. The primarysensing microsystems 100 and 100″ communicate with each other andcooperate with each other to provide an overall optimal control of thehousehold climate.

Illustrated in FIG. 3B is the configuration of FIG. 3A with the additionof the auxiliary sensing microsystem 100′ inserted into the dockingstation 205 that is powered by a building AC outlet. According toembodiments, an additional sensing microsystem, when docked or otherwiseinstalled, will automatically detect and be detected by the existingsensing microsystems by wireless communication. The additional sensingmicrosystem will join in with the existing units to cooperate in unisonfor improved control heating and cooling control functionality. Theadditional information provided by virtue of the temperature sensing,occupancy sensing, etc. provided by the auxiliary sensing microsystem100′ further enhances the quality of overall HVAC system control withrespect to user comfort and/or energy efficiency.

Illustrated in FIG. 3C is the configuration of FIG. 3B with the additionof a second auxiliary sensing microsystem 100 e, which is powered from asolar cell 301 and optionally includes an internal battery that isrecharged by the solar cell 301. The external temperature (andoptionally other sensed data such as outdoor humidity, motion sensing,etc.) sensed by the auxiliary sensing microsystem 100e can beadvantageously used to even further enhance the quality of overall HVACsystem control with respect to user comfort and/or energy efficiency.Although not required, the sensing microsystem 100e can be made simplerthan the sensing microsystems 100, 100′, and 100″ in that the userinterface features can be omitted.

A variety of different docking station types and capabilities, andrelated interchangeabilities of primary and auxiliary sensingmicrosystems, are within the scope of the present teachings. Forexample, in one embodiment there is provided an HVAC-coupled dockingstation (not shown) that provides the required wiring connectivity tothe HVAC unit and that optionally includes power-stealing circuitry. Thevarious docking stations and sensing microsystems can be otherwiseconfigured such that the different sensing microsystems can beinterchanged into different docking stations, including an ability for aprimary sensing microsystem to be placed into a nightstand dockingstation (thereby becoming an auxiliary sensing microsystem) and anability for an auxiliary sensing microsystem to be placed into anHVAC-coupled docking station (thereby becoming a primary sensingmicrosystem).

For one embodiment, all sensing microsystems sold by the manufacturercan be identical in their core functionality, each being able to serveas either a primary sensing microsystem or auxiliary sensing microsystemas the case requires, although the different sensing microsystems mayhave different colors, ornamental designs, memory capacities, and soforth. For this embodiment, the user is advantageously able, if theydesire, to interchange the positions of their sensing microsystems bysimple removal of each one from its existing docking station andplacement into a different docking station. Among other advantages,there is an environmentally, technically, and commercially appealingability for the customer to upgrade to the newest, latest sensingmicrosystem designs and technologies without the need to throw away theexisting sensing microsystem. For example, a customer with a singlesensing microsystem (which is necessarily serving as a primary sensingmicrosystem) may be getting tired of its color or its TFT display, andmay be attracted to a newly released sensing microsystem with adifferent color and a sleek new OLED display. For this case, in additionto buying the newly released sensing microsystem, the customer can buy atabletop docking station to put on their nightstand. The customer canthen insert their new sensing microsystem into the existing HVAC-coupledwall docking station, and then take their old sensing microsystem andinsert it into the tabletop docking station. Advantageously, in additionto avoiding the wastefulness of discarding the old sensing microsystem,there is now a new auxiliary sensing microsystem at the bedside that notonly provides increased comfort and convenience, but that also promotesincreased energy efficiency by virtue of the additional multi-sensorinformation and processing power provided. For another embodiments,there can be a first class of sensing microsystems and associateddocking stations that are specialized for use as primary sensingmicrosystems and interchangeable with each other, but not with a secondclass of sensing microsystems and associated docking stations that arespecialized for use as auxiliary sensing microsystems, and which in turnare interchangeable with each other.

According to embodiments and as described in one or more of the commonlyassigned incorporated applications, supra, a rich variety ofcapabilities is provided when one or more HVAC systems are controlled byone or more of the described sensing microsystems, with particularlyadvantageous operation being provided when plural sensing microsystemsare used as in FIG. 2A and FIGS. 3A-3C. Although a particularly richvariety of capabilities is provided when the network of sensingmicrosystems is connected to the Internet, there is also a rich varietyof capabilities provided even when there is no connection to theInternet. For scenarios in which there is no internet connectivity, thenetwork of sensing microsystems is capable of performing tasksincluding, but not limited to: operating the one or more HVAC systemsaccording to one or more heating/cooling schedules (template schedules)and sensed occupancies; providing a friendly user interface for easymodification of the template schedules and learning about userpreferences and habits by question-and-answer; providing feedback on theuser display regarding energy usage and usage patterns; “learning” aboutthe preferences, habits, and occupancy patterns of the buildingoccupants by virtue of sensor detection patterns, patterns ofthermostatic control inputs, etc.; adapting to the learned preferences,habits, and occupancy patterns by static and/or dynamic modification tothe template schedules; empirically modeling or otherwise characterizingthe capabilities of the one or more HVAC systems and the thermalcharacteristics of the enclosure based on control inputs to the HVACsystem(s) and distributed sensor data (as further facilitated by theoutside weather sensing as facilitated by the externally positionedsensing microsystem 100 e of FIG. 3C); and optimizing empirically and/orby system simulation the control of the one or more HVAC systems basedon the determined thermal characteristics of the enclosure and/or thelearned occupant preferences, habits, and occupancy patterns.

Further layers of advantageous functionality are provided for scenariosin which the sensing microsystems indeed have access to the Internet,the network of sensing microsystems being capable of performing tasksincluding, but not limited to: providing real time or aggregated homeenergy performance data to a utility company, a sensing microsystem dataservice provider, sensing microsystems in other homes, or other datadestinations; receiving real time or aggregated home energy performancedata from a utility company, sensing microsystem service provider,sensing microsystems in other homes, or other data sources; receivingnew energy control algorithms or other software/firmware upgrades fromone or more sensing microsystem service providers or other sources;receiving current and forecasted weather information for inclusion inenergy-saving control algorithm processing; receiving user controlcommands from the user's computer, network-connected television, smartphone, or other stationary or portable data communication appliance(hereinafter collectively referenced as the user's “digital appliance”);providing an interactive user interface to the user through theirdigital appliance; receiving control commands and information from anexternal energy management advisor, such as a subscription-based serviceaimed at leveraging collected information from multiple sources togenerate the best possible energy-saving control commands or profilesfor their subscribers; receiving control commands and information froman external energy management authority, such as a utility company towhom limited authority has been voluntarily given to control the sensingmicrosystem in exchange for rebates or other cost incentives (e.g., forenergy emergencies, “spare the air” days, etc.); providing alarms,alerts, or other information to the user on their digital appliance(and/or a user designee such as a home repair service) based on sensedHVAC-related events (e.g., the house is not heating up or cooling downas expected); providing alarms, alerts, or other information to the useron their digital appliance (and/or a user designee such as a homesecurity service or the local police department) based on sensednon-HVAC related events (e.g., an intruder alert as sensed by thesensing microsystem's multi-sensor technology); and a variety of otheruseful functions enabled by network connectivity.

In view of the rich variety of capabilities provided by the network ofsensing microsystems as described above, it has been found that asignificant tension can arise between providing a network ofeasy-to-install, easy-to-administer, flexible, “lightweight” sensingmicrosystems, while at the same time providing advanced climategovernance functionality that can require significant computing power.Thus, for example, according to one experiment reported in U.S. Pat. No.7,510,126, supra, a “parasitic” or “power-stealing” circuit should drawno more than 55 milliwatts in order for most typical HVAC systems toremain unaffected. With reference to FIGS. 3A-3C, this can substantiallylimit the amount of computational load that can be carried out by theprimary sensing microsystems 100 and 100″ for installations in whichthey are powered by parasitic or power-stealing methods. Likewise, theremay be substantial limits on the amount of incoming or battery-storedsolar power available to the sensing microsystem 100e depending on thetime of day, how sunny the weather is, and other factors. Notably, evenfor the auxiliary sensing microsystem 100′ that derives its power fromthe AC wall outlet, that power level is not necessarily unlimited, butrather is limited by aesthetic design concerns, expense concerns, andheating concerns, including concerns about keeping the weight andbulkiness of “power brick” circuitry within tolerable levels atreasonable costs, and including concerns that relate to heat dissipationby the microprocessor circuitry.

FIG. 4 illustrates a sensing microsystem 100 and a conceptual functionalblock diagram thereof according to an embodiment. The sensingmicrosystem 100 of FIG. 4 can represent, without limitation, either aprimary or auxiliary sensing microsystem. Sensing microsystem 100comprises a core operations module 402, a power management and detectionavailability module 404, a cooperative load balancing module 406, and ashared computing module 408. The modules 402-408 may be implementedusing any of a variety of different architectures without departing fromthe scope of the present teachings, ranging from a first example inwhich they are provided as separate electronic components in electricaland data communication with each other, to a second example in whichthey are provided as separate or integrated software routines forexecution by a common microprocessor, and including any combinationthereof.

The sensing microsystem 100 comprises physical hardware and firmwareconfigurations, along with hardware, firmware, and software programmingthat is capable of carrying out the currently described methods. In viewof the instant disclosure, a person skilled in the art would be able torealize the physical hardware and firmware configurations and thehardware, firmware, and software programming that embody the physicaland functional features described herein without undue experimentationusing publicly available hardware and firmware components and knownprogramming tools and development platforms. By way of example, powersensing circuitry capable of determining an available amount ofdiscretionary power, either on an instantaneous power availability basis(e.g., milliwatts) or an interval-based power availability basis (e.g.,milliwatt-hours) based on incoming external power and/or stored powerlevels are known and commonly used in smartphone and other portabledevice technology. By way of further example, automated methods forcomputational load balancing, including both static methods (i.e., theshared computational task is distributed once among the differentprocessing nodes and carried through to completion at each node) anddynamic methods (i.e., the shared computational task is re-distributedat selected intervals according to changing conditions) are known in theart and discussed generally, for example, in Bourke, Server LoadBalancing, O'Reilly & Associates (2001), and White, et. al., “AConceptual Model for Simulation Load Balancing,” Proc. 1998 SpringSimulation Interoperability Workshop (1998), each of which isincorporated by reference herein.

According to an embodiment, core operations module 402 is configured tocarry out the more basic tasks of the sensing microsystem 100 that wouldnot generally be considered as candidates for load sharing, withexamples including temperature sensing, occupancy sensing, providing auser interface for any walk-up users, and wireless data communicationstasks that communicate associated basic information. For operation as aprimary sensing microsystem, the core operations module 402 wouldfurther carry out comparisons of sensed temperatures to templateschedules and sending appropriate actuation signals to the HVAC systemto which it is coupled. In contrast, shared computing module 408 isconfigured to carry out the more advanced computational tasks whosepromptness of execution would be substantially enhanced by load sharingamong multiple nodes, such as the complex characterization and/oroptimization algorithms discussed above.

System simulation algorithms represent one particular set ofcomputational tasks that can benefit from load sharing. An example of anadvantageous use of system simulation in a climate control environmentwould be to run a series of “what if” or “test cases” based on a modelof the enclosure environment, which can be heavily recursive andtherefore computationally intensive tasks which are relatively difficultfor a single “lightweight” processor to achieve in a reasonable periodof time. A variety of complex computations may also benefit from loadsharing, including machine learning and mathematical optimizationalgorithms relating to system characterization, home occupancyprediction, set point optimization, and other computational goals, whichcan be carried out using one or more known technologies, models, and/ormathematical strategies including, but not limited to, artificial neuralnetworks, Bayesian networks, genetic programming, inductive logicprogramming, support vector machines, decision tree learning, clusteringanalysis, dynamic programming, stochastic optimization, linearregression, quadratic regression, binomial regression, logisticregression, simulated annealing, and other learning, forecasting, andoptimization techniques.

According to an embodiment, power management and availability detectionmodule 404 is configured to determine an amount of electrical poweravailable for dedication to the shared computational task that iscarried out by shared computing module 408. For one embodiment, powermanagement and availability detection module 404 is configured to (a)determine a total amount of electrical power available to the sensingmicrosystem 100, (b) determine the amount of electrical power requiredfor the core operations of the sensing microsystem, those coreoperations including at least one temperature sensing task and at leastone wireless communication task, and (c) determining the amount ofelectrical power that can be dedicated to the shared computing task(i.e., expended by shared computing module 408) based on the differencebetween the total available power and the required core operationspower. For purposes of clarity of description and not by way oflimitation, the amount of electrical power determined to be availablefor dedication to the shared computing task is referenced herein as“spare” electrical power.

According to an embodiment, cooperative load balancing module 406 isconfigured to cooperate with the other sensing microsystems to allocatethe shared computational task thereamong according to the amount of“spare” power available at each of them, that is, the amount of powerthat is available to be dedicated to the shared computing task asdetermined by the power management and availability detection module404. A variety of different strategies and relational architectures canbe used for load balancing among the different sensing microsystemswithout departing from the scope of the present teachings. In oneexample, the load allocation decisions can be dictated solely by one ofthe primary sensing microsystems, such as the primary sensingmicrosystem connected to the HVAC unit in a single-HVAC systeminstallation, based on information reported to it by the auxiliarysensing microsystems. To achieve this with a common code base appliedacross all of the sensing microsystems, each is programmed with a basicself-awareness module in which it is determined whether that module is aprimary sensing microsystem or an auxiliary sensing microsystem.Software switches can then be programmed in such that a different loadbalancing module 406 is actuated depending on whether that unit is aprimary or auxiliary sensing microsystem. The load balancing module 406for the primary sensing microsystem would contain the “master”load-balancing routine that allocates the load, while the load balancingmodules 406 for the auxiliary sensing microsystem would contain the“servant” modules that carry out the decisions of the “master” routine.However, a variety of other strategies and relational architectures,including more democratic methods of load balancing decision making, arealso within the scope of the present teachings.

For one embodiment, the power management and availability detectionmodule 404 is configured to (a) estimate a maximum marginal power beyondthe required core operations power that can be consumed by the sensingmicrosystem without introducing unacceptable error into thermal readingsacquired by its temperature sensor, and (b) limit the determined amountof electrical power available to shared computing module 408 to thatmaximum marginal power if it is less than the difference between thetotal available power and the required core operations power.

Any of a variety of different measurements, metrics, estimations, orexpressions can be used to characterize power availability withoutdeparting from the scope of the present teachings. For one embodiment,the determined amount of “spare” electrical power available is expressedas an analog value in physical units representative of an electricalpower and/or electrical energy level. For another embodiment, determinedamount of “spare” electrical power available is expressed as a logicalvalue representative of one of a predetermined plurality of categoriesgenerally characteristic of an electrical power availability. By way ofexample, in one embodiment the amount of “spare” electrical power can bea simple binary YES or NO, or AVAILABLE or NOT AVAILABLE. In otherembodiments the amount can be expressed on a three-way logical scale,such as HIGH AVAILABILITY, LIMITED AVAILABILITY, and NO AVAILABILITY. Instill other embodiments the amount of “spare” power can be expressed onan N-way logical scale, e.g., a digit between 0 and N−1 where 0represents no availability and N−1 represents a maximum availability.

FIG. 5 illustrates shared computational load distribution in a climatecontrol system having plural sensing microsystems, such as the sensingmicrosystem 100 of FIG. 4, according to an embodiment. At step 502, ateach sensing microsystem, an amount of electrical power available fordedication to the shared computational task is determined. At step 504,each sensing microsystem cooperates with all other sensing microsystemsto allocate thereamong respective portions of the shared computationaltask according to the amount of electrical power determined to beavailable for dedication thereto at each respective sensing microsystem.At step 506, each sensing microsystem carries out its respective portionof the shared computational task.

For one embodiment, the shared computational task is apportioned suchthat each of the sensing microsystems having a greater amount of “spare”electrical power is assigned a heavier associated computational loadthan each of the sensing microsystems having a lesser amount of “spare”electrical power available. For another embodiment, the overallcomputational load is allocated to each sensing microsystem inpercentagewise proportion to the percentage of the overall amount of“spare” electrical power available thereat. For example, if there aretwo sensing microsystems including a first sensing microsystem having75% of the overall available “spare” electrical power and a secondsensing microsystem having 25%, then the shared computational load issplit 75/25 between those sensing microsystems.

For other embodiments in which spare power availability is expressed asa logical value, such as YES or NO, the computational load distributioncan be based on an even division among the YES sensing microsystems. Forexample, if there are three sensing microsystems including a firstsensing microsystem having a “spare” electrical power of NO, and secondand third sensing microsystems each having a “spare” electrical power ofYES, then the shared computational load can be split 50/50 between thesecond and third sensing microsystems.

FIG. 6 illustrates shared computational load distribution in a climatecontrol system having plural sensing microsystems according to anembodiment. At step 602, it is determined whether any of the sensingmicrosystems are connected to continuous line power (such as the sensingmicrosystem 100′ of FIG. 3B), and if so, then the allocation of theshared computational load is weighted toward those sensing microsystemsat step 606. In one example, all or substantially all of the sharedcomputational load is allocated to the sensing microsystem(s) that areconnected to continuous line power. If none of the sensing microsystemsare connected to continuous line power, then step 604 is carried out inwhich the shared computational load is allocated pro rata to eachsensing microsystem in percentagewise proportion to its share of theoverall amount of “spare” electrical power available.

Thus provided according to one or more embodiments is an ability for themultiple sensing microsystems to judiciously share computing tasks amongthem in an optimal manner based on power availability and/or circuitryheating criteria. Many of the advanced sensing, prediction, and controlalgorithms provided with the sensing microsystems are relatively complexand computationally intensive, and can result in high power usage and/ordevice heating if carried out unthrottled. For one embodiment, theintensive computations are automatically distributed such that amajority (or plurality) of them are carried out on a subset of thesensing microsystems known to have the best power source(s) available atthat time, and/or to have known to have the highest amount of storedbattery power available. Thus, for example, because it is generallypreferable for each primary sensing microsystem not to require householdAC power for simplicity of installation as well as for equipment safetyconcerns, primary sensing microsystems will often be powered by energyharvesting from one or more of the 24 VAC call relay power signals ifthere is no common (C) wire provided by the HVAC system, and thereforemay only have a limited amount of extra power available for carrying outintensive computations. In contrast, a typical auxiliary sensingmicrosystem may be a nightstand unit (e.g. docking station 205 in FIG.2A, supra) that can be plugged in as easily as a clock radio. In suchcases, much of the computational load can be assigned to the auxiliarysensing microsystem so that power is preserved in the primary sensingmicrosystem. In another embodiment, the speed of the intensive datacomputations carried out by the auxiliary sensing microsystem (or, moregenerally, any sensing microsystem unit to which the heavier computingload is assigned) can be automatically throttled using known techniquesto avoid excessive device heating, such that temperature sensing errorsin that unit are avoided. In yet another embodiment, the temperaturesensing functionality of the sensing microsystem to which the heaviercomputing load is assigned can be temporarily suspended for an intervalthat includes the duration of the computing time, such that no erroneouscontrol decisions are made if substantial circuitry heating does occur.

Whereas many alterations and modifications of the present invention willno doubt become apparent to a person of ordinary skill in the art afterhaving read the foregoing description, it is to be understood that theparticular embodiments shown and described by way of illustration are inno way intended to be considered limiting. By way of example, althoughthe each of the distributed microsystems in one or more embodimentsdescribed above includes a temperature sensor, in other embodiments oneor more of the distributed microsystems may omit a temperature sensorwhile having one or more other types of sensors (e.g., humidity only,occupancy detector only) that are useful in achieving optimal climatecontrol, and/or that are useful in achieving a particular type ofclimate control.

By way of further example, according to another embodiment there isprovided a method in which it is determined whether data communicationscan be established, or have been established, between one or more of theplurality of lightweight sensing microsystems and an external“heavyweight” node, such as a laptop computer, desktop computer, orother network-attached computing device that does not have a climatesensor or is otherwise normally dedicated to a purpose unrelated toclimate control of that enclosure, and that has a relatively highcomputing capacity and an at least temporary availability to assist inthe shared computational load. If such heavyweight node is available,some or all of the shared computational load is offloaded to thatexternal heavyweight node by preparation of a self-contained package ofexecutable code and source data, and transmission of the self-containedpackage to the external heavyweight node.

By way of further example, it is to be appreciated that the timeintervals for which any particular shared computing task allocation iseffective can range from relatively long intervals (e.g., where the taskassignments are rebalanced once every several minutes to once everyseveral hours based on changed conditions), to very short intervals(e.g., where the task assignments are rebalanced once every few secondsor less based on changed conditions) without departing from the scope ofthe embodiments. Likewise, the time intervals for rebalancing can beinterrupted for various reasons without departing from the scope of theembodiments. Thus, for example, if the network of sensing microsystemsis sharing a large simulation load equally, but then a user walks up toone of the sensing microsystems and begins interacting with that unit,the determined amount of “spare” power for that sensing microsystem canbe instantly set to zero and the load rebalanced over the otheravailable sensing microsystems. As another example, if the network ofsensing microsystems is sharing a large simulation load, but then a userwalks up to one of the sensing microsystems and begins interacting withthat unit, the determined amount of “spare” power for all sensingmicrosystem can be instantly set to zero, thus effectively suspendingthe shared computational task, until the user has walked away, whereuponthe shared computational task can be resumed.

By way of even further example, while computational load balancing amonga plurality of smart, lightweight (e.g., low power) sensing microsystemsaccording to respective spare power availability at those sensingmicrosystems has been found to be particularly advantageous for use inachieving practical, appealing, flexible, scalable, and efficientcontrol of one or more HVAC systems in a climate control systemaccording to one or more of the above-described embodiments, it is to beappreciated that the scope of the present teachings is not so limited.Rather, computational load balancing among a plurality of smart,lightweight (e.g., low power) sensing microsystems for control of one ormore HVAC systems in a climate control system can be based on any of avariety of other criteria, either as adjunct criteria together with thespare power availability criterion, or as alternative stand-alonecriteria, without departing from the scope of the present teachings.Such other criteria upon which the computational load balancing can bebased on factors including, but not limited to: the type ofmicroprocessor included in each sensing microsystem; the type of sensorincluded in each sensing microsystem; the location at which each sensingmicrosystem is installed within or outside the enclosure; the amount andtype of core functionalities for which each respective sensingmicrosystem is responsible; and the amount and type of immediatenon-shared-task related inputs and/or outputs being processed and/orprovided by that sensing microsystem at a physical user interfacethereof and/or by wireless communication therewith. Therefore, referenceto the details of the embodiments are not intended to limit their scope.

1. A climate control system, comprising: a plurality of wirelesslycommunicating sensing microsystems, each said sensing microsystemincluding a temperature sensor and a processor, at least one of saidsensing microsystems being coupled to an HVAC unit for control thereof,said plurality of sensing microsystems being configured to jointly carryout at least one shared computational task associated with the controlof the HVAC unit; and for each said sensing microsystem, a powermanagement circuit configured to determine an amount of electrical poweravailable for dedication to said at least one shared computational task;wherein said at least one shared computational task is apportioned amongrespective ones of said plurality of sensing microsystems according tothe amount of electrical power determined to be available for dedicationthereto at each said respective sensing microsystem.
 2. The climatecontrol system of claim 1, wherein said at least one sharedcomputational task is apportioned such that each of said sensingmicrosystems having a greater amount of electrical power available fordedication to said at least one shared computational task is assigned aheavier associated computational load than each of said sensingmicrosystems having a lesser amount of electrical power available fordedication to said at least one shared computational task.
 3. Theclimate control system of claim 2, said at least one sharedcomputational task being characterized by an overall computational load,said plurality of sensing microsystems having an overall amount ofelectrical power available for dedication to said at least one sharedcomputational task, wherein each said sensing microsystem is assigned tocarry out a percentage of said overall computation load that isproportional to a percentage of said overall amount of electrical powerdetermined to be available at that sensing microsystem.
 4. The climatecontrol system of claim 2, said at least one shared computational taskbeing characterized by an overall computational load, said plurality ofsensing microsystems including a first sensing microsystem coupled tothe HVAC unit and powered by a call relay power-stealing circuit, saidplurality of sensing microsystems including a second sensing microsystempowered from a continuous line power source, wherein the at least oneshared computational task is apportioned such that a majority of theoverall computational load is assigned to said second sensingmicrosystem.
 5. The climate control system of claim 4, whereinsubstantially all of said overall computational load is assigned to saidsecond sensing microsystem.
 6. The climate control system of claim 1wherein, for each of said sensing microsystems, said determined amountof electrical power available for dedication to said at least one sharedcomputational task is expressed as an analog value in physical unitsrepresentative of an electrical power and/or electrical energy level. 7.The climate control system of claim 1, wherein, for each of said sensingmicrosystems, said determined amount of electrical power available fordedication is expressed as a logical value representative of one of apredetermined plurality of categories generally characteristic of anelectrical power availability for dedication to said at least one sharedcomputational task.
 8. The climate control system of claim 7, whereinsaid predetermined plurality of categories is selected from the groupconsisting of: available/not available; high availability/lowavailability/no availability; and high availability/mediumavailability/30 low availability/not available.
 9. The climate controlsystem of claim 1, wherein said power management circuit of each saidsensing microsystem is configured to determine said amount of electricalpower available for dedication to said at least one shared computationaltask according to the steps of: determining a total amount of electricalpower available to the sensing microsystem; determining an amount ofelectrical power required for a core functionality of the sensingmicrosystem that is distinct from said at least one shared computationaltask, said core functionality including at least one temperature sensingtask and at least one wireless communication task; and determining theamount of electrical power available for dedication to said at least oneshared computational task based on a difference between said totalavailable power and said required core functionality power.
 10. Theclimate control system of claim 7, wherein said determining the amountof electrical power available for dedication further comprises:estimating a maximum marginal power beyond said required corefunctionality power that can be consumed by said sensing microsystemwithout introducing unacceptable error into thermal readings acquired bysaid temperature sensor; and limiting said determined amount ofelectrical power available for dedication to said maximum marginal powerif said maximum marginal power is less than said difference between saidtotal available power and said required core functionality power. 11.The climate control system of claim 1, wherein said at least one sharedcomputational task is selected from the group consisting of:environmental system characterization based on historical controlsignals applied to the HVAC system and thermal responses thereto asmeasured by said temperature sensors; environmental system simulation;and computation of one or more optimal HVAC control strategies based onenvironmental system characterization and simulation.
 12. A method ofoperation for a plurality of wirelessly communicating sensingmicrosystems of a distributed climate control system, each sensingmicrosystem including a temperature sensor and a processor, at least oneof the sensing microsystems being coupled to an HVAC unit for controlthereof, the plurality of sensing microsystems cooperating to controlthe HVAC unit based at least in part on temperature readings acquired bythe plurality of temperature sensors, the plurality of sensingmicrosystems being configured to jointly carry out at least one sharedcomputational task associated with the control of the HVAC unit, themethod comprising: at each sensing microsystem, determining an amount ofelectrical power available for dedication to the at least one sharedcomputational task; allocating among the sensing microsystems respectiveportions of the least one shared computational task according to theamount of electrical power determined to be available for dedicationthereto at each respective sensing microsystem; and at each sensingmicrosystem, carrying out the respective portion of the least one sharedcomputational task allocated thereto.
 13. The method of claim 12,wherein said at least one shared computational task is allocated suchthat each of said sensing microsystems having a greater amount ofelectrical power available for dedication to said at least one sharedcomputational task is assigned a heavier associated computational loadthan each of said sensing microsystems having a lesser amount ofelectrical power available for dedication to said at least one sharedcomputational task.
 14. The method of claim 13, said at least one sharedcomputational task being characterized by an overall computational load,said plurality of sensing microsystems including a first sensingmicrosystem coupled to the HVAC unit and powered by a call relaypower-stealing circuit, said plurality of sensing microsystems includinga second sensing microsystem powered from a continuous line powersource, wherein the at least one shared computational task is allocatedsuch that a majority of the overall computational load is assigned tosaid second sensing microsystem.
 15. The method of claim 12 wherein, foreach of said sensing microsystems, said determined amount of electricalpower available for dedication to said at least one shared computationaltask is expressed as an analog value in physical units representative ofan electrical power and/or electrical energy level.
 16. The method ofclaim 12, wherein, for each of said sensing microsystems, saiddetermined amount of electrical power available for dedication isexpressed as a logical value representative of one of a predeterminedplurality of categories generally characteristic of an electrical poweravailability for dedication to said at least one shared computationaltask.
 17. The method of claim 16, wherein said predetermined pluralityof categories is selected from the group consisting of: available/notavailable; high availability/low availability/no availability; and highavailability/medium availability/low availability/not available.
 18. Acomputer readable medium tangibly embodying one or more sequences ofinstructions wherein execution of the one or more sequences ofinstructions by a plurality of processors contained in a respectiveplurality of wirelessly communicating sensing microsystems of adistributed climate control system causes the plurality of sensingmicrosystems to: cooperatively control an HVAC unit based at least inpart on temperature readings acquired by a plurality of temperaturesensors located respectively in said plurality of sensing microsystems;and carry out at least one shared computational task associated withsaid cooperative control of the HVAC unit, comprising: at each sensingmicrosystem, determining an amount of electrical power available fordedication to the at least one shared computational task; and allocatingamong the sensing microsystems respective portions of the least oneshared computational task according to the amount of electrical powerdetermined to be available for dedication thereto at each respectivesensing microsystem.
 19. The computer readable medium of claim 18,wherein said at least one shared computational task is selected from thegroup consisting of: environmental system characterization based onhistorical control signals applied to the HVAC system and thermalresponses thereto as measured by said temperature sensors; environmentalsystem simulation; and computation of one or more optimal HVAC controlstrategies based on environmental system characterization andsimulation.
 20. The computer readable medium of claim 18, wherein saidat least one shared computational task is allocated such that each ofsaid sensing microsystems having a greater amount of electrical poweravailable for dedication to said at least one shared computational taskis assigned a heavier associated computational load than each of saidsensing microsystems having a lesser amount of electrical poweravailable for dedication to said at least one shared computational task.21. The computer readable medium of claim 20, said at least one sharedcomputational task being characterized by an overall computational load,said plurality of sensing microsystems including a first sensingmicrosystem coupled to the HVAC unit and powered by a call relaypower-stealing circuit, said plurality of sensing microsystems includinga second sensing microsystem powered from a continuous line powersource, wherein the at least one shared computational task is allocatedsuch that a majority of the overall computational load is assigned tosaid second sensing microsystem.
 22. The computer readable medium ofclaim 18 wherein, for each of said sensing microsystems, said determinedamount of electrical power available for dedication to said at least oneshared computational task is expressed as an analog value in physicalunits representative of an electrical power and/or electrical energylevel.
 23. The computer readable medium of claim 18, wherein, for eachof said sensing microsystems, said determined amount of electrical poweravailable for dedication is expressed as a logical value representativeof one of a predetermined plurality of categories generallycharacteristic of an electrical power availability for dedication tosaid at least one shared computational task.
 24. The computer readablemedium of claim 23, wherein said predetermined plurality of categoriesis selected from the group consisting of: available/not available; highavailability/low availability/no availability; and highavailability/medium availability/low availability/not available.